It seems to me as if the problem here is that the overall OpenACS cleanup was quite effective, maybe too effective: The code in with_finally (in acs-tcl) assumes, that the global variable errorInfo always exists. If it does not exist, it throws the error. So, the relation to xotcl is very vague (maybe there is a call in the xotcl startup that sets as a side effect this variable).

The local build issue of xotcl2 (nsf2) appears to be due to Freebsd10 having clang (not gcc) installed by default. I'm installing gcc since install-ns specifies CC=gcc for it; if only to keep the build consistent with development experience.